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» CVE-2021-39136
baserCMS is an open source content management system with a focus on Japanese language support. In affected versions there is a cross-site scripting vulnerability in the file upload function of the management system of baserCMS. Users are advised to update as soon as possible. No workaround are available to mitigate this issue.
NVD Status： Modified ，CVE State: published
Threat Intelligence & Risk Assessment for CVE-2021-39136
Conclusion & alert: CVE-2021-39136 is rated Moderate Risk (54.3/100) : CVSS High severity, with medium exploitation likelihood (EPSS 0.90%).Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
Exploit prediction scoring system (EPSS) score for CVE-2021-39136
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
#
Date
Old EPSS score
New EPSS score
Delta (New - Old)
1
2026-06-15
0.54%
0.90%
+0.36%
2
2025-09-05
0.66%
0.54%
-0.12%
3
2025-03-30
—
0.66%
—
Full EPSS history
(11 records total)
Common vulnerability scoring system (CVSS) metrics for CVE-2021-39136
CVSS metrics for this CVE.
Base score
Version
Severity
Vector
Exploitability
Impact
Score source
8.7
3.1
HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
2.3
5.8
[email protected]
5.4
3.1
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
2.3
2.7
[email protected]
3.5
2.0
LOW
AV:N/AC:M/Au:S/C:N/I:P/A:N
Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
6.8
2.9
[email protected]
Weakness enumeration for CVE-2021-39136
GitHub Security Advisory for CVE-2021-39136
GHSA-hgjr-632x-qpp3 · Severity: high · Ecosystem: composer
— Cross-site scripting vulnerability in file upload
Affected software / configurations for CVE-2021-39136
Vendor
Product
Version
Raw CPE
basercms
basercms
< 4.5.1
cpe:2.3:a:basercms:basercms:*:*:*:*:*:*:*:*
References for CVE-2021-39136
cvelogic
Threat Intelligence